As someone already stated in the comments, once you've found the perfect angle, the only goal is to run back and forth getting more soldiers. The physics-based destruction was also a good idea, I think it would perfectly fit into your game's humor.
Personnaly, the problems I has was that firstly, the soldiers still had their colliders active while being dragged into the castle, which means they often got stuck in the stairs and the roof when I was about to reach the next floor. I would also like to see the run button mapped to the second shift button, it would be practical for the poor unfortunate left-handed people like me, who still live under the tyranny of the despotic right-handed.
Also, an alternative button for the E key, for the same reason as above. The last problem is that, since you start in your castle's garden and you have to carry the soldiers inside, you always start with a disadvantage compared to the opponent, whose cannon is always locked on you and already inflicts damage to you before you've even fired your first hit.
With all that said, let's talk about the pros: I really enjoy the premice of this game, having to litteraly use your own people as cannon fodders to destroy the enemy ; even when you carry them, they stay in that T-pose completely ignoring you, adding even more wierdness to that ludcrous scene. For a game made in 72 hours, this is really not bad at all,considering you had to create every 3D model yourself, thing that I didn't do because I was too afraid on wasting crucial time on it and not enough in gameplay.
Now, if you've sat through my wall of text, I have only two words left : Good job ;)